The application will address the leading cause of death for adolescents, motor vehicle crashes. In 2010, there were more than 887,000 police reported motor vehicle crashes (MVCs) involving teen drivers resulting in 2,387,139 people involved in MVCs with a teen behind-the-wheel. Teen drivers account for a disproportionate number of fatal and nonfatal injuries from motor vehicle crashes. Evidence is emerging that comprehensive parenting programs and on-road driver assessment and feedback can optimize the learner's permit period and possibly reduce crashes. The long-term goal of this research is to identify effective programs that can reduce adolescents' risk for motor vehicle crashes (MVCs). The current best-practice policy approach to teen driver MVC prevention are state-level Graduated Driver Licensing (GDL) programs; however, GDL's success has come from its focus on restricting access to high risk contexts and not on directly improving novice adolescent drivers' competence. While additional public health benefit can be obtained by directly addressing this issue, existing training programs and models have not been successful. Therefore, there is a critical unmet need for novel efficacious interventions that target young drivers' inexperience directly to complement the strong and policy-level structure put in place by GDL. The current application addresses this need. In the proposed study we will evaluate a comprehensive program that consists of both parent- and teen-directed components. For teens, there is a state-of-the art on-road driver assessment (ODA). The ODA is completed by a certified driving rehabilitation specialist (CDRS) who provides tailored feedback on the teens' performance and verbally reinforces use of the parent intervention components. For parents, there are face-to-face parent sessions with a trained facilitator and learning-to-drive handbook. These are designed to improve parent engagement across a wide range of parenting behaviors related to the learner and intermediate periods of GDL. This comprehensive parent-teen intervention (PTI) improves on existing programs by jointly targeting both parents and teens and utilizes data from R03HD082664 that indicates the ODA reduces crash risk by an estimated 53%. We propose a randomized controlled trial with 1,200 parent-teen dyads to evaluate our central hypothesis, which is that the comprehensive parent- and teen-directed intervention administered during the learner period of GDL can reduce the proportion of adolescent drivers who are in a motor vehicle crash (MVC) during the first 12 months of licensure compared to a usual practice control condition.